The invention relates to an apparatus for shaping wire.
Apparatus for shaping wire is disclosed in U.S. Pat. No. 5,363,681 (WAFIOS FTU 3). This apparatus has a flange (118) which is firmly attached to the bearing body and is provided with a prismatic part (140) on which a radially adjustable wire guide attachment (136) is provided which has an eccentric wire guide bore (137) and which cooperates with a cutting tool (14). The wire guide (130) ending at the attachment (136) always rotates synchronously with the intake roller pairs about the wire axis. This apparatus has already been modified in such a way that the prismatic part at the now rotatable flange, as one unit together with the wire holding attachment, can be guided in a circular movement around the wire axis so that the friction between the wire and the attachment can be eliminated. This is also suggested by DE 197 36 468 A1 (ITAYA) in which, however, the stationary wire guide (80) between the stationary wire intake rollers (14 and 15) on the one hand, and the rotatable wire holder (70) on the other hand, generates friction when the wire is twisted about its lengthwise axis.
A particularity of DE 197 36 468 A1 is a remote controlled rotatable wire grip (64) provided at the rotatable wire guide (70) for non-rotatable clamping of the wire whereby said wire guide can not turn the wire about its own axis like clamping intake rollers do.
It is the object of the present invention to considerably improve the geometric shape accuracy of the three-dimensional wire bodies produced by the apparatus for shaping wire disclosed by U.S. Pat. No. 5,363,681 and this with an unchanging result, and to increase the output of the apparatus, i.e. to achieve a quality increase of finished workpieces and a performance increase of the apparatus for shaping three-dimensional workpieces.
This is achieved by the invention at first by the fact that the outlet wire guide installed rigidly at the bearing body of the rotatable wire intake device of the apparatus for shaping wire according to U.S. Pat. No. 5,363,681 is replaced by a known rotatable wire guide, and secondly, that the rotatable wire guide is equipped according to this invention with a programmably controlled and power controlled wire xe2x80x9cbrakingxe2x80x9d device, the shaping process servomotor of which is controlled by the machine control together with the servomotors of the other device aggregates of the apparatus.
Due to the common but separately arranged xe2x80x98rotating wire intakexe2x80x99 and xe2x80x98rotating wire guidexe2x80x99 the azimuthal friction during a synchronous run is completely eliminated, since no relative movement between the wire intake and the wire guide takes place when the wire is turned. This is of special advantage, because the friction between the wire and the wire guide during the shaping process leads to inaccuracies in the workpiece geometry. Further, xe2x80x98unlimitedxe2x80x99 turning of the wire (to-and-fro) is possible even when the wire guide stands.
It goes without saying that the rotating wire intake and the rotating wire guide can also be operated asynchronously.
The aforementioned advantage of friction elimination can be optimized by the wire brake device according to the invention which operates programmably controlled and power controlled in each individual section of operation of the workpiece to be produced. The braking pressure on the wire can be programmably controlled in such a way that during the shaping process, for example, when an already finished part of the workpiece in the wire shaping area turns down, a damping effect is generated. Or with an appropriate programmably controlled brake pressure, a supporting or stabilizing effect can be obtained during shaping operations of the standing wire so that the wire and, if necessary, its already finished portion can not twist in its angular position. Further, the brake pressure on the incoming wire can be determined by the computer in such a way that, for example, during winding the play between the incoming wire and the wire guide is reduced so precisely that an exact spring form and spring pitch is obtained during the winding process, whereas feeding of the wire is still possible.
Thus it will be possible to compensate for too much play between the wire and the guide resulting, for example, from wear of the wire guide (enlarged wire guide bore), or from too much play resulting from wire diameter tolerances.
These improvements on every individual production section will considerably increase the quality of the finished workpieces and this in a constant way even for large scale manufacturing.